cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A050204 a(n) is the number of n X n matrices of 0's, 1's and -1's in which the entries in each row or column sum to 1.

Table of values

n a(n)
1 1
2 2
3 21
4 1344
5 628080
6 2030271480
7 49846153939785
8 9350902053107858880
9 13807842729396124460629536
10 162526525004284727135887319788800
11 15464071313054035722739424623204673044920
12 12011244510939290610945342901003078567310643860160

List of values

[1, 2, 21, 1344, 628080, 2030271480, 49846153939785, 9350902053107858880, 13807842729396124460629536, 162526525004284727135887319788800, 15464071313054035722739424623204673044920, 12011244510939290610945342901003078567310643860160]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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